1. Field of the Disclosure
The present invention relates to patient interface devices for transporting a gas to and/or from an airway of a user, and, in particular, to a patient interface device including a patient contacting component, such as a mask having a mask cushion, that has a ribbed patient contacting surface.
2. Description of the Related Art
There are numerous situations where it is necessary or desirable to deliver a flow of breathing gas non-invasively to the airway of a patient, i.e., without intubating the patient or surgically inserting a tracheal tube in their esophagus. For example, it is known to ventilate a patient using a technique known as non-invasive ventilation. It is also known to deliver positive airway pressure (PAP) therapy to treat certain medical disorders, the most notable of which is obstructive sleep apnea (OSA). Known PAP therapies include continuous positive airway pressure (CPAP), wherein a constant positive pressure is provided to the airway of the patient in order to splint open the patient's airway, and variable airway pressure, wherein the pressure provided to the airway of the patient is varied with the patient's respiratory cycle. Such therapies are typically provided to the patient at night while the patient is sleeping.
Non-invasive ventilation and pressure support therapies as just described involve the placement of a patient interface device including a mask component having a soft, flexible cushion on the face of a patient. The mask component may be, without limitation, a nasal mask that covers the patient's nose, a nasal cushion having nasal prongs that are received within the patient's nares, a nasal/oral mask that covers the nose and mouth, or a full face mask that covers the patient's face. Such patient interface device may also employ other patient contacting components, such as forehead supports, cheek pads and chin pads. The patient interface device interfaces the ventilator or pressure support device with the airway of the patient, so that a flow of breathing gas can be delivered from the pressure/flow generating device to the airway of the patient. It is known to maintain such devices on the face of a wearer by a headgear having one or more straps adapted to fit over/around the patient's head.
Current mask cushions are of a singular, thin curved flap design that contacts the skin surface of the patient. The single flap, combined with a wide thin surface area, contribute to the formation of channels which allow air to escape. This makes it very difficult to achieve a positive seal on a wide variety of patient faces. Additionally, the escaping air sometimes induces unwanted vibrations in the cushion which often results in loud, unpleasant noises similar to flatulence. Similar problems may also presented by other patient contacting components of patient interface devices.